This application is related to U.S. patent application Ser. No. 09/930,557, entitled xe2x80x9cPOWER SYSTEM INCLUDING HEAT REMOVAL UNIT FOR PROVIDING BACKUP POWER TO ONE OR MORE LOADS,xe2x80x9d filed Aug. 15, 2001; U.S. patent application Ser. No. 09/930,394, entitled xe2x80x9cMETAL FUEL CELL SYSTEM FOR PROVIDING BACKUP POWER TO ONE OR MORE LOADS,xe2x80x9d filed Aug. 15, 2001; U.S. Provisional Application No. 60/318,685, entitled xe2x80x9cULTRA-LONG DURATION BACKUP FOR CRITICAL APPLICATIONS USING ZINC/AIR REGENERATIVE FUEL CELLS,xe2x80x9d filed Sep. 10, 2001; U.S. Provisional Application No. 60/328,838, entitled xe2x80x9cULTRA-LONG DURATION BACKUP FOR TELECOMMUNICATIONS APPLICATIONS USING ZINC/AIR REGENERATIVE FUEL CELLS,xe2x80x9d filed Oct. 11, 2001, U.S. patent application Ser. No. 09/973,490, entitled xe2x80x9cMETHODS OF PRODUCING OXYGEN REDUCTION CATALYST,xe2x80x9d filed Oct. 9, 2001; U.S. patent application Ser. No. 10/060,965, entitled xe2x80x9cRECIRCULATING ANODE,xe2x80x9d filed on even date herewith; U.S. patent application Ser. No. 10/072,856, entitled xe2x80x9cMANIFOLD FOR FUEL CELL SYSTEM,xe2x80x9d filed on even date herewith; U.S. patent application Ser. No. 10/066,544, entitled xe2x80x9cFUEL CELL SYSTEM,xe2x80x9d filed on even date herewith; and U.S. patent application Ser. No. 10 050,901, entitled xe2x80x9cPOLYMER COMPOSITES, CATHODES, AND SYSTEMS THEREOF,xe2x80x9d filed on even date herewith. Each of these applications is hereby fully incorporated by reference herein as though set forth in full.
This invention relates generally to power supplies for providing primary and/or auxiliary/backup power to electrical equipment, and, more specifically, to power supply systems based on metal- or hydrogen-fuel cells.
A great deal of electronic equipment in the modern world relies upon high-quality, reliable electrical power. Such equipment, each a load, includes, for example and without limitation, lawn and garden equipment; radios; telephone; targeting equipment; battery rechargers; laptops; communications devices; sensors; night vision equipment; camping equipment (including without limitation, stoves, lanterns, lights, and the like); lights; vehicles (including without limitation, cars, recreational vehicles, trucks, boats, ferries, motorcycles, motorized scooters, forklifts, golf carts, lawnmowers, industrial carts, passengerxe2x80x94carts (airport), luggage handling equipment (airports), airplanes, lighter than air crafts (e.g., blimps, dirigibles, and the like), hovercrafts, trains (e.g., locomotives, and the like), and submarines (manned and unmanned); torpedoes; security systems; electrical energy storage devices for renewable energy sources (e.g., solar-based, tidal-based, hydro-based, wind-based, and the like); many other types of electrical devices, equipment for which a primary and/or backup power source is necessary or desirable to enable the equipment to function for its intended purpose, military-usable variants of above, and the like; and suitable combinations of any two or more thereof. Over the past decade, as the digital age has taken hold, there has been an explosive growth in the deployment of such equipment.
For many applications of such equipment, power outages can lead to losses of use or data, equipment damage, missed deadlines, and/or lost productivity, and therefore must be avoided. At the same time, the reliability of the traditional power generation, transmission, and distribution network has fallen in some countries due in part to the increased demands which have been placed on this network throughout the world. The result is that power grid-independent primary and/or auxiliary/backup power supplies have emerged as a means for providing primary and/or backup power to such equipment.
The invention provides a fuel cell system for providing primary and/or auxiliary/backup power (with or without regeneration unit on board, and with or without capability of refueling from a refueling station) to one or more loads selected from the group comprising: lawn and garden equipment; radios; telephone; targeting equipment; battery rechargers; laptops; communications devices; sensors; night vision equipment; camping equipment (including without limitation, stoves, lanterns, lights, and the like); lights; vehicles (including without limitation, cars, recreational vehicles, trucks, boats, ferries, motorcycles, motorized scooters, forklifts, golf carts, lawnmowers, industrial carts, passenger carts (airport), luggage handling equipment (airports), airplanes, lighter than air crafts (e.g., blimps, dirigibles, and the like), hovercrafts, trains (e.g., locomotives, and the like), and submarines (manned and unmanned); torpedoes; security systems; electrical energy storage devices for renewable energy sources (e.g., solar-based, tidal-based, hydro-based, wind-based, and the like); many other types of electrical devices, equipment for which a primary and/or backup power source is necessary or desirable to enable the equipment to function for its intended purpose, military-usable variants of above, and the like; and suitable combinations of any two or more thereof.
The fuel cell system provides primary and/or auxiliary/backup power to the one or more loads. For primary power, the fuel cell system provides power upon sensing a demand for power from the one or more loads. For back/auxiliary power, the fuel cell system provides power upon the occurrence of a power outage condition, defined to include a disruption or discontinuation in the delivery of system-external primary power (i.e., power from a primary source, namely, a source other than the fuel cell system) to the one or more loads. The system comprises one or more fuel cells, each comprising a power source and a fuel storage unit, that deliver primary and/or auxiliary/backup power to the one or more loads upon the occurrence of a power outage condition. In one aspect, the invention further provides that each fuel cell can optionally further comprise a regeneration unit to regenerate the reactants of the fuel from the reaction products, and/or a reaction product storage unit to store the reaction products from the fuel cell, and/or a second reactant storage unit to store the second reactants. The one or more fuel cells can be metal fuel cells (including without limitation zinc fuel cells, aluminum fuel cells, lithium fuel cells, sodium fuel cells, magnesium fuel cells, iron fuel cells, and the like), hydrogen fuel cells, methanol fuel cells, ethanol fuel cells, and/or any other fuel cells that have the same purpose.
In a further embodiment, the fuel cell useful in the practice of the invention system comprises a metal fuel cell. In another aspect, a metal fuel cell system for providing primary and/or auxiliary/backup power to one or more loads selected from the previously described group has one, or any suitable combination of two or more, of the following properties: the system can be configured to not utilize or produce significant quantities of flammable fuel or product, respectively; the system can provide primary and/or auxiliary/backup power to the one or more loads selected from the previously-described group for an amount of time limited only by the amount of fuel present (e.g., in the range(s) from about 0.01 hours to about 10,000 hours or more); the system can be configured to have an energy density in the range(s) of about 35 Watt-hours per kilogram of combined fuel and electrolyte added to about 400 Watt-hours per kilogram of combined fuel and electrolyte added; the system can further comprise an energy requirement, and can be configured such that the combined volume of fuel and electrolyte added to the system is in the range(s) from about 0.0028 L per Watt-hour of the system""s energy requirement to about 0.025 L per Watt-hour of the system""s energy requirement; the system can be configured to have a fuel storage unit that can store fuel at an internal pressure in the range(s) from about xe2x88x925 pounds per square inch (psi) gauge pressure to about 200 psi gauge pressure; the system can be configured to hold a pre-charge of fuel in the power producing cell(s) of the power source of the metal fuel cell, optionally in an amount sufficient to permit operative engagement of the fuel cell(s) at a rate significantly faster than when no such fuel is present and/or sufficient to supply power for a time in the range(s) of about 0.001 minutes to about 100 minutes or more without additional fuel being added; and the system can be configured to expel substantially no reaction products outside of the system (e.g., into the environment).
The system further optionally comprises a controller that, upon sensing demand for power from the load (for primary power) or upon sensing the occurrence of a power outage condition (for auxiliary/backup power), operatively engages the one or more metal fuel cells and/or engages a flow of the one or more second reactants at a time prior to in the range(s) from about 10 microseconds to about 10 seconds after the controller senses the occurrence of a power outage condition. Optionally, the controller can be configured to sense a cessation of the power demand condition (for use of system as primary power source). In addition or alternatively, the controller can be configured to sense a cessation of the power outage condition (for use of system as auxiliary/backup power source) and, responsive thereto, to engage the primary power (from a source external to the system) to provide power to one or more of the optional regeneration units in the one or more fuel cells and/or to disengage the one or more fuel cells from providing power to the one or more loads. The system can also optionally further comprise a power converter to convert to alternating current (AC), or to another form of direct current (DC), the DC power output by the one or more fuel cells.
In one implementation, the system of the invention further optionally comprises means for physically supporting the one or more fuel cells, and at least one of the one or more loads. Optionally, the means for supporting can be configured to support one or more of the remainder of the one or more loads, the controller, and/or the optional power conversion stage.
Each of these two means, as well as each of the other components of the system, can be separate from, or integral with, one or more of the other components of the system.
In addition, the invention provides methods of providing primary and/or auxiliary/backup power to one or more loads selected from the previously described group comprising, upon sensing demand for power from the load (for use of system as primary power source) or upon sensing an outage of primary power to the one or more loads (for use of system as auxiliary/backup power source), operatively engaging one or more fuel cells to provide power to the one or more loads. The invention also provides methods of pre-charging a fuel cell system for providing primary and/or auxiliary/backup power to one or more loads selected from the previously described group comprising placing an amount of fuel in cell cavities of a power source of a fuel cell system prior to operative engagement of the fuel cell system. The invention further provides methods of utilizing a pre-charged fuel cell system for providing primary and/or auxiliary/backup power to one or more loads selected from the previously described group, comprising operatively engaging a fuel cell system containing fuel in cell cavities of a power source of the fuel cell system prior to its operative engagement for a time in the range from about 0.001 minutes to about 100 minutes without adding additional fuel thereto.
Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.